Give expression in both tuple calculus and domain calculus, Database Management System

Assignment Help:

Consider the following relational schema:
Doctor(DName,Reg_no)
Patient(Pname, Disease)
Assigned_To (Pname,Dname)
Give expression in both Tuple calculus and Domain calculus for every of the queries:
(i) Get the names of patients who are assigned to more than one doctor.
(ii) Get the names of doctors who are treating patients with ‘Polio'.

Ans:
(i)Tuple Calculus:
{p[PName] | p ∈ PATIENT ∧ ∃a1, a2 (a1 ∈ ASSIGNED_TO ∧ a2 ∈ ASSIGNED_TO ∧
p[PName] = a1[PName] ∧ a1[PName] = a2[PName] ∧ a1[DName] ≠ a2[DName])}
Domain Calculus:
{p | ∃p1, d1, p2, d2 ( ∈ PATIENT ∧ ∈ ASSIGNED_TO ∧
ASSIGNED_TO ∧ p1 = p2 ∧ d1 ≠ d2)}
(ii)Tuple Calculus:
{u[Dname] | u ∈ ASSIGNED_TO ∧ ∃t (t ∈ PATIENT ∧ t[Disease] = ‘Polio' ∧
t[PName] = u[PName])}
Domain Calculus:
{d | ∃p1, p2, s2 ( ∈ ASSIGNED_TO ∧ ∈ PATIENT
∧ p1 = p2 ∧ s2 = ‘Polio')}


Related Discussions:- Give expression in both tuple calculus and domain calculus

Explain the concept of two-phase locking, Explain the Concept of Two-phase ...

Explain the Concept of Two-phase Locking It concerns the positions of locking and unlocking operations in each transaction.  In this protocol every transaction issue lock and u

Modular growth, Modular growth: In distributed environments, it is simple t...

Modular growth: In distributed environments, it is simple to expand. Latest sites can be added to the network without affecting the operations of other sites, as they are somewhat

Security and integrity, Security And Integrity After Reading the concep...

Security And Integrity After Reading the concepts of database recovery in the last section, let us now deal with a vital concept that helps in minimizing consistency errors in

Explain authorization and integrity manager, Explain Authorization and Inte...

Explain Authorization and Integrity Manager ? Authorization and Integrity Manager: Tests for the satisfaction of integrity constraints and checks the authority of users to acce

Define 2nf normal form, 2NF Normal Form : A relation schema process R i...

2NF Normal Form : A relation schema process R is in 2NF if it is in 1NF and each non-prime attribute A in R is fully functionally related on primary key. Second normal form (2N

What is a relationship called when it is maintained entities, What is a rel...

What is a relationship called when it is maintained between two entities? A relationship is called Binary relationship when it is maintained between two entities.

Describe integrity and security, Describe integrity and security? a)   ...

Describe integrity and security? a)      Domain constraint b)      Referential integrity A value that appears in one relation for a given set of attributes also appear fo

Define about the stored procedure, Define about the Stored Procedure - ...

Define about the Stored Procedure - It's a set of T-SQL statements combined together to perform a single task formed by combining numerous small tasks. - When you essentiall

State the meaning of object representation, State the meaning of Object Rep...

State the meaning of Object Representation  The term object representation means "to represent object with the help of objects model symbols". Implementing objects is too simp

Central database schema, Consider an information system designed for an onl...

Consider an information system designed for an online company which provides IT products and services. These include desktops, laptops, networking products, IT books, parts, and te

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd